Is the application $\tau$ bijective? If so, specify $\tau^{-1}$. Is the expression of $\tau^j$ found in question I.A.2 for $j \in \mathbb{N}$ valid for $j \in \mathbb{Z}$?
Is the application $\tau$ bijective? If so, specify $\tau^{-1}$. Is the expression of $\tau^j$ found in question I.A.2 for $j \in \mathbb{N}$ valid for $j \in \mathbb{Z}$?